Stem Cells for Corneal Engineering

角膜工程干细胞

• 批准号: 9212811
• 负责人: JAMES L FUNDERBURGH
• 金额: $ 38.72万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-04-15 至 2019-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9212811
• 关键词: Adopted; Alpha Cell; Asses; Automobile Driving; Biomedical Engineering; Blindness; Cadaver; Cell Therapy; Cell surface; Cells; Cicatrix; Clinical; Collagen; Connective Tissue; Cornea; Corneal Injury; Corneal Opacity; Corneal Stroma; Cues; Engineering; Environment; Enzymes; Extracellular Matrix; Failure; Fibroblasts; Goals; Healthcare; Immune response; Immunosuppressive Agents; In Vitro; Individual; Knowledge; LOXL2 gene; Link; Maintenance; Mediating; Mesenchymal; Modeling; Molecular; Mus; Myofibroblast; N-Cadherin; Natural regeneration; Neutrophil Infiltration; Outcome; Penetrating Keratoplasty; Phenotype; Population; Preparation; Procedures; Property; Proteoglycan; Role; Solid; Source; Stem cells; Stromal Cells; TSG-6 protein; Testing; Therapeutic; Thick; Time; Tissue Engineering; Tissues; Transplanted tissue; Work; World Health; Wound Healing; base; blind; cadherin-11; corneal scar; crosslink; cytokine; daughter cell; experimental study; healing; human adult stem cell; human stem cells; improved; in vivo; in vivo Model; insight; macrophage; mouse model; novel; prevent; public health relevance; reconstitution; regenerative; self-renewal; stem cell population; tissue regeneration; tool

 DESCRIPTION (provided by applicant): Corneal opacity is a source of blindness for millions worldwide. Penetrating keratoplasty (PK) using cadaveric corneas is highly successful, but donated tissue is in limited supply and over time PK grafts are subject to a significant rate of complications and failure. Developing better therapy for corneal opacity is world health-care need that has inspired this project. In the 10 years of this project we have identified stem cells from human corneal stroma (CSSC) and showed that these cells (a) differentiate to keratocytes, (b) produce corneal stromal tissue in vitro, and (c) prevent formation of corneal scars in mouse models in vivo. The long-term goal of the project is develop stem cell-based therapeutic applications that can treat or reverse corneal scarring reducing the need for PK. In the renewal of the project we will work toward this goal with three specific aims. CSSC but no other stromal cells express N-cadherin (NCad). Aim 1 will test the hypothesis that NCad identifies a population of cells with keratocyte differentiation potential and provides a cell surface marker useful for isolating cells with high potential to effect corneal regeneration. We have found that CSSC can secrete connective tissue with aligned collagen and proteoglycans similar to corneal stroma. Aim 2 will test the role of microstructure topology and stiffness of solid substrates in directing the composition and organization of this CSSC-secreted matrix. The aim will also test the role of collagen crosslinking enzymes LOXL2 and TGM2 in increasing the strength and stiffness of the matrix elaborated by CSSC. This aim will assemble multilamellar constructs by stacking of the engineered tissue sheets. These experiments will provide insights on how the 3D environment directs secretion and organization of transparent stromal tissue. We have recently shown that CSSC instilled in healing corneal wounds prevent scarring and reconstitute ablated tissue with matrix indistinguishable from native cornea. Aim 3 will investigate how CSSC induce this tissue regeneration. CSSC reduce infiltration of neutrophils and induce the presence of TGFß3, a cytokine attributed to induce scarless wound healing. This aim will test the hypothesis that via secretion of TSG-6 protein, CSSC reduce neutrophil infiltration and influence macrophages to adopt an alternative activated (M2) phenotype stimulating tissue regeneration by secretion of TGFß3. The impact of these studies will be identification of novel molecular mechanisms controlling corneal stromal tissue matrix synthesis and organization. Of particular potential significance is identification of a mechanism to induce regeneration of native mammalian tissue. There will also be progress toward the goal of clinical use of CSSC. Thicker, stronger, and more organized tissue constructs will be produced with increased potential for use in lamellar grafts. Identification of properties linked to immunosuppressive and regenerative potential for CSSC will improve potential for use of these cells in cell-based therapy.

 描述(申请人提供)：角膜混浊是全世界数百万人失明的来源。使用身体角膜的穿透性角膜移植(PK)是非常成功的，但捐赠的组织供应有限，随着时间的推移，PK移植物的并发症和失败率很高。开发更好的治疗角膜混浊的方法是世界卫生保健需求的灵感所在。在这个项目的10年中，我们已经从人角膜基质(CSSC)中鉴定出干细胞，并表明这些细胞(A)分化为角质细胞，(B)在体外产生角膜基质组织，(C)在小鼠体内模型中防止角膜瘢痕的形成。该项目的长期目标是开发基于干细胞的治疗应用，可以治疗或逆转角膜疤痕，减少对PK的需求。在项目的更新中，我们将以三个具体目标努力实现这一目标。CSSC无其他间质细胞表达N-钙粘附素(NCad)。目的1验证NCad识别具有角膜细胞分化潜能的细胞群的假设，并为分离具有高潜能的影响角膜再生的细胞提供有用的细胞表面标记。我们发现CSSC可以分泌结缔组织和类似于角膜基质的胶原和蛋白多糖。目的2将测试固体基质的微结构、拓扑结构和硬度在指导CSSC分泌基质的组成和组织方面的作用。目的还将测试胶原交联酶LOXL2和TGM2在增加CSSC阐述的基质强度和硬度方面的作用。这一目标将通过堆叠工程组织片来组装多层结构。这些实验将提供有关3D环境如何指导透明间质组织的分泌和组织的见解。我们最近发现，植入CSSC用于修复角膜伤口可防止瘢痕形成，并重建基质与天然角膜难以区分的消融组织。目的3将研究CSSC如何诱导组织再生。CSSC可减少中性粒细胞的渗透，并诱导转化生长因子3的存在，这是一种被认为能诱导无疤痕伤口愈合的细胞因子。本研究旨在验证CSSC通过分泌TSG-6蛋白减少中性粒细胞的渗透，并通过分泌转化生长因子β3影响巨噬细胞采用另一种激活的(M2)表型刺激组织再生的假说。这些研究的影响将是确定控制角膜基质组织基质合成和组织的新的分子机制。特别具有潜在意义的是确定一种诱导本土哺乳动物组织再生的机制。CSSC的临床应用目标也将取得进展。更厚、更坚固、更有组织的组织结构将被生产出来，并增加用于板层移植的潜力。识别与CSSC的免疫抑制和再生潜力相关的特性将提高这些细胞在细胞治疗中的使用潜力。